spirv: Builtin Layer is an input for fragment shaders

This change makes it so we emit a load_input intrinsic when Layer
is read in a fragment shader.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c
index 917aa9d84a2753a3984e3e02fb719168ad06b66f..a38d3593f4379baf83d9d54c25a78693196a2648 100644 (file)
--- a/src/compiler/spirv/vtn_variables.c
+++ b/src/compiler/spirv/vtn_variables.c
@@ -819,7 +819,12 @@ vtn_get_builtin_location(struct vtn_builder *b,
       break;
    case SpvBuiltInLayer:
       *location = VARYING_SLOT_LAYER;
-      *mode = nir_var_shader_out;
+      if (b->shader->stage == MESA_SHADER_FRAGMENT)
+         *mode = nir_var_shader_in;
+      else if (b->shader->stage == MESA_SHADER_GEOMETRY)
+         *mode = nir_var_shader_out;
+      else
+         unreachable("invalid stage for SpvBuiltInLayer");
       break;
    case SpvBuiltInViewportIndex:
       *location = VARYING_SLOT_VIEWPORT;